What to Do When Your Microwave Stops Heating

June 14, 2018 Published by Leave your thoughts

Did your microwave suddenly stop heating, or stop working altogether? If so, don’t toss it out just yet—it may only need a simple fix to start functioning properly again. You might even be able to perform DIY microwave repair in Addison, TX! Below, we take a look at what to do when your microwave stops heating.

Microwave not heating

If your microwave is not heating properly, perform this test before you despair. Pour cold water into a microwave-safe cup or dish, put it in the microwave and set the dial to 30 seconds or so. After it beeps, carefully remove the cup and cautiously test the temperature of the water using your finger. The water should be hot. If it’s not hot, put it back in for another 30 seconds, then again if needed. The water should be hot after 60 to 90 seconds—if not, your microwave is not heating properly.

There are several things that can cause microwaves to stop heating, such as a malfunctioning diode, a burned out high-voltage capacitor or transformer or an overheated thermoprotector.

Test the high voltage diode

A microwave that turns on but doesn’t heat up could be having a problem with the high voltage diode. This is what powers the magnetron. Since the diode is in the cabinet, start by unplugging the microwave, and after removing the cabinet, discharge the high voltage capacitor. Use a multimeter to test the diode for continuity—in a working diode there should be low resistance in one direction and high resistance in the other. No continuity or low resistance in both directions means the diode needs to be replaced. A diode that tests normal requires a qualified technician.

Check the door switch

If the door switch (also called an interlock switch) is broken, then it cannot send signals to microwave components to supply power when it closes, nor to stop heating when the door is open. Having a faulty switch doesn’t mean the fan and motors will stop functioning—in fact, this can make the microwave look like it’s working just fine.

To access the door switch, unplug the unit and then remove the cabinet. (Switches are typically labeled C for common and NO for normally open.) While depressing the actuator button, use a multimeter to check the switches. If there is no continuity right away, the switch needs to be replaced. During the test, make sure the door hooks and triggers the door switch to work properly.

Test the magnetron

A lack of heat could be due to a broken magnetron. When it breaks, it may blow a fuse in your microwave and cause other components to fail. Before testing the magnetron and grabbing wires, unplug the unit, remove the cabinet and discharge the high voltage capacitor. You’ll have to attach multimeter leads to the magnetron terminals to test continuity. Hire a professional if you are not comfortable doing this.

Whenever you are in need of appliance repair in Addison, TX, contact Appliance Champion Dallas. Call us to schedule an appointment anytime!

Categorised in: ,

Leave a Reply

Your email address will not be published. Required fields are marked *